1. Field of the Invention
The present invention relates to a substrate processing apparatus and a substrate processing method which supplies a processing liquid to a top rim portion of a substrate to thereby perform a predetermined surface processing to the top rim portion, the substrate including semiconductor wafers, glass substrates for photomask, glass substrates for liquid crystal display, glass substrates for plasma display, substrates for FED (field emission display), substrates for optical disks, substrates for magnetic disks, substrates for magnet-optical disks, etc.
2. Description of the Related Art
In a production process in which a series of processing is performed to the substrates such as semiconductor wafers, a film forming processing is performed for the purpose of forming a various kinds of thin films on the substrate surface. In this film forming processing, the film is sometimes formed on a rear surface of the substrate or a rim portion of the substrate top surface. However, it is only a circuit-forming region at the central portion of the substrate top surface that requires the film to be formed on the substrate in general. And when the films are formed either on the rear surface of the substrate or on the rim portion of the substrate top surface, the following problems may occur. To be more specific, the thin film formed on a rim portion of the substrate top surface may peel off due to a contact with other apparatus during post-processing of the film forming processing. And, the peeled-off thin film may adhere to the circuit-forming region at the central portion of the substrate top surface and to the substrate processing apparatus, which may cause reduced yield of the fabricated products and a trouble of the substrate processing apparatus itself.
Consequently, for the purpose of removing the thin films formed on the rear surface of the substrate and the top rim portion of the substrate, an apparatus described in JP-A-2006-41444, for example, is proposed. In this apparatus, a supporting section is provided projecting upward from a spin base and supports the substrate while abutting on a rim portion of the rear surface of the substrate. The substrate with the thin film formed on the top surface thereof is held horizontally with its top surface facing up. Then, inert gas is supplied from an atmosphere blocking plate (equivalent to an “opposed member” of this invention) disposed above the substrate toward the top surface of the substrate to a space formed between the atmosphere blocking plate and the substrate to press the substrate to the supporting section, whereby the substrate is held by the spin base. And then, the substrate is rotated in a condition that the substrate is held by the spin base. Further, chemical solution, as a processing liquid, is supplied toward the top rim portion of the rotating substrate from a nozzle inserted into a nozzle insertion hole disposed on a rim portion of the atmosphere blocking plate. Consequently, the undesired substance adhering to the top rim portion of the substrate is removed by etching. Furthermore, the chemical solution, as the processing liquid, is supplied to the rear surface of the rotating substrate. Consequently, the chemical solution spreads all over the rear surface of the substrate, thereby removing by etching the undesired substance on the rear surface of the substrate. In this way, the thin films are removed by etching on the substrate rear surface and only on the rim portion of the substrate top surface.